They are going to be offering a return to line accommodation.
I've traveled to WDW with my cousin with MS. It was my trip in 2009 when we ran the half marathon! She ran it, too. She travels to WDW pretty much every year. Her condition is kind of cyclical (is that the right word?) where sometimes her MS is debilitating, and she needs to rent a
scooter. Other times it's not, and walking and running is actually good for her and helps reduce the affects of MS. She has become an avid runner since her diagnosis, and being a runner has kept her symptoms more manageable for much of the time (not all the time). However, one issue she has is that she can't ride thrill rides and roller coasters anymore. For many people with MS, rides like those affect their condition and exacerbates their symptoms.
So, depending on symptoms, people with MS can rent a scooter. They can use the return to line option. If they want shorter lines, they can buy
Genie+. There are lots of options available depending on their need on a given day!
I think there are a lot of people on here trying to claim that DAS is needed for them, but Disney will be offering other accommodations that are better suited to address the needs of various medical conditions and disabilities.